Issue
When signing in to a Microsoft 365 desktop app (such as Word or Excel) using your Microsoft 365 user ID and password, you receive the error message:
- "Sorry, another account from your organization is already signed in on this computer."
Cause
This message is displayed when trying to sign in using a Microsoft 365 account that is from the same organization as a Microsoft 365 account that is already logged into Office on the same computer.
Solution
The account you want to use to edit the document with the Microsoft 365 desktop app (Word/Excel etc) needs to match the account you are using in FYI.
- Log out of FYI.
- Sign out of any Microsoft 365 accounts that are signed in.
In this example, user Frank Marshall is already logged in, but you are trying to log in as user Mia Jones.
In the top right-hand corner of a Microsoft 365 app (Word, Excel), select your name or initials, and then select Sign out. - Restart your computer.
- Log into FYI again. Sign back into the Microsoft 365 application.
Note: If the issue has not been resolved by the above steps, refer to step 4 of this Microsoft troubleshooting guide. Whilst the guide is written for Office 2013, the process is similar. We recommend contacting your IT team for assistance prior to making any changes.
The registry location for Office 365 is "Computer\HKEY_CURRENT_USER\Software\Microsoft\Office\16.0\Common\Identity\Identities"
More information
In Microsoft 365 apps, you can access Microsoft 365 content in SharePoint Online by providing your Microsoft 365 user ID and password. If you have multiple Microsoft 365 user IDs from different organizations, you can access content from the SharePoint Online deployments of each organization.
However, Microsoft 365 only supports one Microsoft 365 user sign-in from each tenant or organization per session.
Microsoft 365 makes the best effort to prevent a second user from signing in when another user from the same organization is already signed in. However, there may be cases in which this scenario is not detected and the Microsoft 365 user interface may show that another user is successfully signed in. In this case, the second user cannot access his or her content. All Microsoft 365 content that a user tries to open will be performed by using the first user’s credentials.
Be aware that Microsoft 365 respects the permissions of all documents and SharePoint Online libraries. That is, if the first user doesn’t have access to a document that the second user has access to, and the second user (who believes they are signed in) attempts to open that document, the document will not
References:
"Sorry, another account from your organization is already signed in on this computer" in Office 2013